<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<body>
  <!-- 
    动画不是重点内容
   -->
   <!-- css3 新特性 -->
   <!-- 
      border-radius
      text-overflow
      rgba
      transition
      transform
      animation
   -->
</body>
</html>